1. Technical Field
The present disclosure is directed to a catheter assembly adapted for use in a catheterization procedure. Specifically, the present disclosure relates to insertion sheaths and stylets for use during implantation of a catheter assembly during a hemodialysis procedure.
2. Description of the Related Art
Catheters are flexible medical instruments for use in the withdrawal and introduction of fluids to and from body cavities, ducts, and vessels. Catheters have particular application in hemodialysis procedures, in which blood is withdrawn from a blood vessel for treatment and subsequently returned to the blood vessel for circulation through a patient's body.
Many hemodialysis catheters include multiple lumens, e.g., dual or triple-lumen catheters, with one lumen being dedicated to the withdrawal of fluid from a vessel, and at least one other lumen being dedicated to the return of fluid to the vessel. Generally, the lumen through which fluid is withdrawn is referred to as the “arterial” lumen, and the lumen through which fluid is returned is referred to as the “venous” lumen. During an exemplary hemodialysis procedure, after placement of a multiple lumen catheter in a patient, blood is withdrawn from the patient through the arterial lumen of the catheter, and is directed to a hemodialysis unit for dialysis, i.e., to remove waste and toxins from the blood. The dialyzed blood is then returned to the patient through the venous lumen of the catheter.
Various techniques are employed for the insertion of hemodialysis catheters including, e.g., the use of guidewires, introduction stylets, and the like. During such procedures, the stylet is inserted through the catheter and is used to facilitate introduction of the catheter en route to a target site. After placement of the catheter, the stylet is removed, and a proximal end of the catheter is fluidly connected to a catheter hub, with or without extension tubes. One insertion technique is disclosed in U.S. Pat. No. 5,509,897 to Twardowski et al., the contents of which are incorporated herein in their entirety.
Generally, hemodialysis catheters are categorized as either acute or chronic in nature. Acute catheters are designed to be placed in a patient under emergent circumstances where delays in placement are unacceptable, and typically remain in place for only a few days. Chronic catheters, by contrast, typically remain in place for extended periods of time, and may be implanted via surgical dissection, e.g., at the patient's bedside, or in an ambulatory surgical setting.
In general, more rigid catheters are easier to insert when compared to more flexible catheters due to kinking and buckling that results during advancement of the catheter through the patient's tissue. As such, acute catheters are often more rigid than chronic catheters given the urgency of placement. While more flexible catheters may have a reduced risk of patient trauma, and may result in increased patient comfort, these catheters normally require the use of an insertion device to assist in placement, e.g., an insertion sheath or stylet.
It would thus be advantageous to provide structure employable in the placement of flexible catheters to achieve the benefits of insertion associated with rigid catheters without compromise regarding reduced patient trauma and increased patient comfort.